Dilation systems and related methods

ABSTRACT

Devices and methods permit dilation of a track of a body to any of a plurality of diameters using a single integrated device that can reach any of a plurality of expanded diameters upon actuation by a user of an actuating mechanism which directs and controls the dilation of a dilating element to which it is connected by a dial and transmission mechanism. A variety of dials, transmission mechanisms and dilating elements are disclosed which may be combined in a variety of ways.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority to and the benefit of U.S.provisional patent application serial Nos. 60/060,217 and 60/087,294filed on Oct. 1, 1997 and May 29, 1998 respectively which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

[0002] The present invention generally relates to dilation systems andrelated methods of their use. The systems and methods are for gainingaccess to portions of a patient's body by a physician, for example toobtain percutaneous access to the kidney by a urologist or a radiologistfor nephrolithotomy. In particular, the present invention relates todilation systems throughout the length of the opening and methods fordilating a track opening to a desired size and maintaining that openingwith a single device.

BACKGROUND INFORMATION

[0003] Current procedures for forming a track in a patient involve firstpiercing the flank of the patient and, for example, the kidney with asmall needle for initial access. Proper imaging verifies the correctplacement. The track is then opened to a desired size by any of avariety of methods.

[0004] In a first method, a balloon catheter, back loaded with a sheath,is inflated to an appropriate pressure. This pressure provides theradial force to dilate the track. After the track is dilated, a sheathis passed over the balloon to maintain the track opening. For differenttrack sizes, an array of balloons of varying sizes are needed becausethe maximum dilation force is obtained only when the balloon is fullyinflated. For each different size balloon catheter, a different sizedsheath must be used. This method of dilation, however, as opposed to thesecond method of renal dilators and sheaths, provides equal radial forcearound the circumference of the balloon and along its length (so called“continuous dilation”). It is generally preferred for this reason andbecause it minimizes trauma to the patient. However, balloons are proneto inflate with irregularities when the resistance of the surroundingtissues is irregular such as encountered with segments of scar tissues.The weakest area of the tissue is dilated faster forming a waist, theremaining tissue is dilated as the inflation pressure is increased, butat a slower rate. This phenomenon is referred to as “waisting.”

[0005] A second currently used method of dilation involves the use ofseveral passive renal dilator and sheaths. The renal dilator shearstissue as it is introduced into the track. The passive dilator is aplastic tube with a bullet tip; the passive sheath is a hollow tube.Both dilators and sheaths have specific preset diameters. For example,the size of renal dilators range in diameter from 8F to 30F inincrements of about 2F (F refers to “French,” a unit of measurement ofdiameter, where 1 F=0.013 inch). An 8F dilator is first used to dilatethe track, followed by substitution of incrementally larger dilatorsuntil the desired track size is obtained. Thus, multiple exchanges ofdilators are necessary. This method causes undesirable shearing oftissue.

[0006] In a third method, an elongate tube made of elastic material suchas rubber is mounted and stretched longitudinally onto a rod, thusdecreasing the radial size of the tube. The mounted tube is insertedinto a track opening and released from the rod, thus increasing theradial size of the tube to its original size. Using this system, oneneeds a series of tubes having varying radial sizes to fit the desiredtrack opening. Selection of the desired size tube permits the dilationof a track opening in one step. However once a tube is selected andpositioned, the size of the track cannot be modified.

[0007] In a fourth method, the dilators have a tapered distal end formedby a compacted slit tube or a series of foil wrapped onto one another toform a cone which may be gradually expanded by manual insertion of a rodwithin the interior of the dilator until the wall of the dilator'sdistal end have become parallel.

[0008] In yet another method, a mesh tube is introduced percutaneouslyin the body using a needle and stylet. Once placed into the body, theneedle and the stylet are removed from the mesh and a passive dilator isinserted manually to expand the radius of the mesh tube. Using thissystem, still several passive dilators are needed to gradually reachedthe desired track size.

[0009] A major inconvenience of these methods is that for each desiredtrack diameter, one must use a specific dilator or balloon and aspecific sheath. The limited availability of sizes for these componentslimits the availability of track sizes that maybe obtained. Further,once these components are inserted, the track size cannot beconstricted.

SUMMARY OF THE INVENTION

[0010] To overcome the deficiencies of these methods, the presentinvention provides dilation systems and related methods in whichprogressive dilation to a desired track size is accomplished using anactuation device with a dial-a-size functionality integrated into asingle device. Further, dilation to a desired track size and maintenanceof the track opening are also integrated into a single device. Theintegrated device provides increased versatility and flexibility to thephysician. Further, the dilation systems of the present inventionprovides for the homogeneous application of radial forces along thelength of the dilating element, and homogeneous resistance againstcountering radial forces applied to the dilating element by the more orless compliant surrounding tissues of the body opening into which thedilating element is inserted. Several dilation systems are presented inthe detailed description that follows which combine in a variety of waysvarious dilating elements and actuation mechanisms. The elements of eachof the systems described specifically hereinafter may be combined withone another to achieve other acceptable dilation systems that result infunctionally similar devices.

[0011] In one aspect of the invention, the dilation systems includes adilating element and an actuation mechanism, the latter interfacesbetween the dilating element and the user. The dilating element can beradially expanded to any of a plurality of diameters. The dilation ofthe dilating element is directed and controlled by the actuationmechanism. Similarly, once dilated, the dilating element may be radiallyconstricted to any of a plurality of diameter using the actuationmechanism.

[0012] In one embodiment of the dilation system, the dilating element isa rolled foil. The rolled foil may be used alone or in combination withother dilating elements. The rolled foil develops radial outward forceswhen compressed to a diameter smaller than its original resting diameterand inward radial forces when dilated larger than its original restingdiameter. When used from an initial compressed state the rolled foil ispreferably used as a dilating element and also as a sheath once in thedilated state. When used from an initial resting state to a dilatedstate the foil is preferably used as a sheath in combination withanother dilating element of the invention. Other embodiments of thedilating elements suitable for use in combination with the rolled foilare, but not limited to, the following: malecots; jacks; parallelograms;balloons; wire baskets; pivots; telescopic cannulas, chain links;longitudinal springs, meshes and braids. These elements may be used as asingle unit or a series of them arranged head-to-tail, within the rolledfoil. In one embodiment, two rolled foils may be used as dilatingelement, one in a compressed state contained within the lumen of theother one, the other one in the resting state.

[0013] In another embodiment, the rolled foil includes a series oflocking mechanisms that permits the selection and retention of a varietyof dilated or compressed diameters.

[0014] In one embodiment the locking mechanisms includes two series ofinterfitting structures, one series is located on a segment of the foil,the other series is located on a second segment of the foil spatiallyproximal to the first series. The series of interfitting structure maybe bumps and notches, protrusions and recesses, tongues and recesses,tongues and holes, and rivets and holes. In another embodiment, thelocking mechanism further includes a trigger which interfaces betweenthe two series of interfitting structures to facilitate the locking andreleasing of the locking mechanism by engaging or disengaging of the oneseries of interfitting structure vis-a-vis the other. In one embodiment,the locking mechanism provides the locking of motion unidirectionally toprevent for example either excessive dilation or deflation of thedilating element. In another embodiment, the locking mechanism providesthe locking of motion bidirectionally.

[0015] Certain embodiments of the dilating element provide dilationalong a certain length of a track of a body without forming a waist.Waistless dilating elements include a combination of a hard ornoncompliant expandable cover with a variety of dilating elements. Hardor non-compliant expandable covers include, but are not limited to, thefollowing: rolled foils, meshes and braids. Suitable dilating elementsinclude, but are not limited to, any one, or a series of one, of thefollowing: malecots; jacks; chain links; longitudinal springs;parallelograms; balloons; wire baskets; telescopic cannulas, and pivots.A preferred embodiment at least includes a rolled foil. Anotherpreferred embodiment includes a balloon covered by a mesh or braid.

[0016] In other preferred embodiments, the dilating element is coveredby other expandable sheaths, such as expandable membranes, nonexpandablemembranes may also be used as sheath but require to be compacted on thedeflated dilating element.

[0017] The actuating mechanism includes a dial and a transmissionmechanism. The dial and the proximal end of the transmission mechanismare housed in a handle. The handle and the dial includes a series ofmarkings or indices graduated preferably in unit of French or othersuitably unit proportional to the diameter of the dilating element. Thedial can occupy a variety of configurations in relation to the handle,each configuration identified by a different index and for selection bythe user. The dial is connected to the proximal end of the transmissionmechanism within the handle. In some embodiments, the dial is connecteddirectly to the transmission mechanism, if no amplification of motion isrequired. In some other embodiments the dial is indirectly connected tothe transmission mechanism, through an amplifying mechanical structure.

[0018] Also in some embodiments, the dial is directly actuated by theuser and transfer motions from the user to the transmission mechanism.Yet in other embodiments, the dial indirectly transfers motions from theuser to the transmission mechanism. For example, the dial includes anelectronic interface which include, but is not limited to, a powersource, a circuitry, a series of switches, and a motor connected to thetransmission mechanism.

[0019] In some embodiments, the transmission mechanism transfers amotion of the dial to the dilating element. The motion may either belongitudinal or rotational. In these embodiments, the transmissionmechanism includes at least one tubular member such as, but not limitedto, cannulas, rods, shafts, or needles.

[0020] In some other embodiments the transmission mechanism converts andtransfers motions from the dial to the dilating element. In theseembodiments the transmission mechanism includes at least a tubularmember and at least one thread. In some other embodiments the tubularmember includes two threads. In certain embodiments one thread islocated at the proximal end of the tubular member for engagement withthe dial, the other at the distal end for engagement with the dilatingelement. In other embodiments, the two threads are located in the distalend, one for engagement with the proximal end of the dilating element,the other for engagement with the distal end of the dilating element.

[0021] In another aspect, the invention is directed to methods fordilating a track of a body. In one embodiment the method includes thefollowing steps: insertion in the track of a dilating element capable ofexpanding to any of a plurality of diameters; expansion of the dilatingelement to any of a plurality of diameters. The expansion of thedilating element is controlled by the user which actuates the actuationmechanism. In other embodiments, the methods also include the step ofintroducing a sheath over the dilating element in a dilated state tomaintain the track dilated to the diameter selected from the pluralityof diameters. Yet other embodiments of the methods include the step ofremoving the dilating element from the track.

[0022] Alternatively, the dilating element may be removed after havingbeen deflated to any of a plurality of diameter inferior to the diameterof the dilated state.

[0023] In certain embodiments of the methods according to thisinvention, the dilating element is first inserted into the track of abody and then dilated. Yet in other embodiments, the dilating element isfirst dilated, then inserted into the track of a body in the dilatedstate.

[0024] Additional objects and advantages of the invention will be setforth in part in the description which follows, and in part will beobvious from the description, or may be learned by practice of theinvention. The objects and advantages of the invention will be realizedand attained by means of the elements and combinations particularlypointed out in the appended claims.

[0025] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

[0026] The accompanying drawings, which are incorporated in andconstitute a part of this specification, illustrate several embodimentsof the invention and together with the description, serve to explain theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIGS. 1A-1C show perspective schematic representations of adilation system of the invention: dilating element alone, FIG. 1A;dilating element in combination with the activation mechanism, FIG. 1B;dilating element in combination with the actuation mechanism and handle,FIG. 1C.

[0028]FIG. 1D shows a cross-sectional representation of the dilationsystem of FIGS. 1A-1C dilating a nephrostomy track.

[0029]FIG. 2 shows a longitudinal sectional schematic representation ofan embodiment of the dilation system of the invention, in the compressedstate (solid lines), and dilated state (broken lines).

[0030] FIGS. 3A-3B show cross-sectional schematic representation ofseparate embodiments of locking mechanisms for use in dilation systemsof the invention, with a partial view only for FIG. 3B.

[0031] FIGS. 4A-4F show cross-sectional schematic representation ofseparate embodiments of locking mechanisms with partial views only forFIGS. 4E and 4F.

[0032]FIG. 5 shows a partial cross-sectional schematic representation ofone embodiment of locking and releasing mechanisms for use in a dilationsystem of the invention.

[0033]FIG. 6A shows a partial cross-sectional schematic representationof an embodiment of a bidirectional locking mechanism for use indilation system of the invention.

[0034]FIG. 6B shows a partial cross-sectional schematic view of anembodiment of a unidirectional locking mechanism for use in dilationsystems of the invention.

[0035] FIGS. 6C-6D show respectively a top view of the upper segment andbottom view of the lower segment of the embodiment of FIG. 6A.

[0036]FIG. 6E shows a perspective schematic view of the dilating elementfeaturing the locking mechanism of FIG. 6A.

[0037] FIGS. 7A-7B show cross-sectional views of an embodiment of adilating element according to the invention.

[0038] FIGS. 7C-7D show the top and side views of an embodiment of adilation system having dilating element of FIGS. 7A-7B.

[0039]FIG. 7E shows a perspective view of the embodiment of the dilationsystem of FIGS. 7C-7D.

[0040] FIGS. 8A-8I show schematic views of various dilating elementshaving a passive dilating element combined with various active dilatingelements according to the invention, with a perspective view for FIG. 8Aand longitudinal sectional views for FIGS. 8B-8I.

[0041]FIG. 9A shows a perspective view of one embodiment of the dilationsystems according to the invention.

[0042] FIGS. 9B-9C show portions of the perspective view of FIG. 9A:FIG. 9B show a distal portion and FIG. 9C shows a proximal portion.

[0043] FIGS. 9D-91 show in various schematic views of the embodiment ofFIG. 9A: a perspective view in FIG. 9D; a top view in FIG. 9F; a sideview in FIG. 9G; a longitudinal sectional view in FIG. 9H; a side viewin FIG. 91, and a distal portion of a perspective view in FIG. 9E.

[0044]FIG. 10A shows a portion of a longitudinal sectional view of oneembodiment of a dilating element and transmission mechanism according tothe invention.

[0045]FIG. 10B shows a cross sectional view of the transmissionmechanism of FIG. 10A.

[0046]FIG. 10C shows a perspective view of a portion of the transmissionmechanism of FIG. 10A.

[0047]FIG. 11 shows a portion of a longitudinal sectional view of oneembodiment of dilating element and transmission mechanism according tothe invention.

[0048]FIG. 12 shows a portion of a longitudinal sectional view of oneembodiment of the dilating element and transmission mechanism accordingto the invention.

[0049]FIG. 13 shows a cross-sectional view of the embodiment of FIG. 12.

[0050] FIGS. 14A-14C show portions of longitudinal sectional views ofthree related embodiments of the dilation system according with theinvention: FIG. 14A with one unit of a dilating element; FIG. 14B withfive units of the same dilating element disposed in a series; FIG. 14Cwith two units of the same dilating element disposed in a series.

[0051]FIG. 15A shows a perspective view of one embodiment of a dilationsystem according to the invention with a locking mechanism.

[0052]FIG. 15B shows a side view of the embodiment of FIG. 15A.

[0053]FIG. 16 shows a side view of the distal end of a dilation systemhaving a series of dilating element of FIG. 15B.

[0054]FIG. 17 shows a cross-sectional view of a distal portion of anembodiment of the dilation system according to the invention having adilating element and portion of the actuation mechanism.

[0055] FIGS. 18A-18C shows various portions of a cross-sectional view ofthe distal end of one embodiment of the dilation system according to theinvention; FIG. 18A; relaxed state of the dilating element; FIG. 18B,compressed state of the dilating element; FIG. 18C transmissionmechanism and dilating element.

[0056]FIG. 19 shows a cross-sectional view of a portion of the dilationsystem of FIG. 18C with a sheath.

[0057]FIG. 20 shows a side view of one embodiment of a dilation systemwith a portion of transmission mechanism according to the invention.

[0058]FIG. 21 shows a side view of one embodiment of a dilation systemwith a portion of transmission mechanism according to the invention.

[0059]FIG. 22 shows a side view of one embodiment of a dilation systemwith a portion of transmission mechanism according to the invention.

[0060]FIG. 23A shows a side view of one embodiment of a dilation systemwith a portion of transmission mechanism according to the invention.

[0061]FIG. 23B shows a perspective view of the dilating element of FIG.23A.

[0062]FIG. 24A shows a perspective view of a embodiment of a componentof a dilating element according to the invention.

[0063]FIG. 24B shows a side view of a series of components of FIG. 24Aforming a dilating element in a relaxed configuration with a portion ofthe transmission mechanism.

[0064]FIG. 24C shows a perspective view of the dilating element of FIG.24B in a dilated, compressed state.

[0065]FIG. 24D shows a front view of the dilating element of FIG. 24C.

[0066]FIG. 25 shows a side view of one embodiment of a dilation systemwith a portion of transmission mechanism according to the invention.

[0067]FIG. 26A shows a longitudinal sectional view of the distal end ofone embodiment of the dilation system of the invention.

[0068]FIG. 26B shows a perspective view of a component of the embodimentof FIG. 26A.

[0069]FIGS. 26C, 26D and 26F show longitudinal sectional views of theembodiment of FIG. 26A at various stages of operation.

[0070]FIG. 26E shows a portion of a perspective view of component of theembodiment of FIG. 26A.

[0071] FIGS. 27A-27E shows various views of an embodiment of thedilation system, of the invention with the top view in FIG. 27A; theside view in FIG. 27B; the perspective view in FIG. 27C; the front viewin FIG. 27D; and the longitudinal cross sectional view in FIG. 27E.

[0072] FIGS. 28A-28D show various views of a component of the handle ofthe dilation system shown in FIGS. 27A-27E, with the top view in FIG.28A; the side view in FIG. 28B; the perspective view in FIG. 28D; andthe front view in FIG. 28D.

[0073] FIGS. 29A-29D show various views of another component of thehandle of the dilation system shown in FIGS. 27A-27E, with the frontview in FIG. 28A; the side view in FIG. 29B; the top view in FIG. 29C;and the perspective view in FIG. 29D.

[0074] FIGS. 30A-30D show various views of another component of thedilation system shown in FIGS. 27A-27E with the perspective view in FIG.30A; the side view in FIG. 30B; the front view in FIG. 30C; and anotherperspective view in FIG. 30D.

[0075] FIGS. 31A-31E show various views of another component of thedilation system shown in FIGS. 27A-27E with the perspective view in FIG.3A; the side view in FIG. 31B; the top view in FIG. 31C; the front viewin FIG. 31D; and the bottom view in FIG. 31E.

[0076] FIGS. 32A-32D shows various views of another component of thedilation system shown in FIGS. 27A-27E with the top view in FIG. 32A;the front view in FIG. 32B; the perspective view in FIG. 32C; and theside view in FIG. 32D.

[0077] FIGS. 33A-33B shows two views of an embodiment of the dilationsystem of the invention with a longitudinal section in FIG. 33A; and across section of the distal end in FIG. 33B.

[0078] FIGS. 34A-34B shows two longitudinal sectional views of anembodiment of the dilation system of the invention: in the deflatedstate in FIG. 34A, and in the dilated state in FIG. 34B.

DESCRIPTION

[0079] To achieve the objects and in accordance with the purpose of theinvention, as embodied and broadly described herein, the inventivedilation systems and methods integrate dilation and user actuation in asingle device. More specifically, the dilation systems and methodscombine a dilating element to open a track in a patient and an actuationmechanism to interface with the dilating element and the user. Thesecombined elements in a single dilation system provide progressive radialexpansion (dilation) and/or force dilation that dilates a track openingto any desired size (from, for example, any of 8F to 30F) with minimumtrauma or tear to the tissue. These dilation systems eliminate theexchange of multiple separate dilators.

[0080] The progressive radial expansion of the dilating element may beperformed continuously or by small discrete increments. Also, dilationmay be interrupted and resumed to reach various dilation sizes in stagesas desired or required by the procedure without exchanging or withdrawalof the device from the track. In some cases, the apparatus of thepresent invention permits to reduce the size of the dilating elementafter reaching the desired targeted dilated state or once the procedureis completed. This permits to minimize trauma to the tissue. Also, itfacilitates the removal of the dilating element, in particular when thedilating element is also used as a sheath or prosthesis.

[0081] Dilating elements of the present invention come in twocategories: 1) active dilating elements; 2) passive dilating elements.An active dilating element is an element that tends to spontaneouslydilates with no additional forces and/or the dilation of which iscontrolled directly by the actuation device, e.g., balloons, tubularradial spring, malecots. Active dilating elements may be used alone in asingle dilation systems or may be used in combination with a passivedilating element to provide greater versatility or improved functionalcharacteristics. A passive dilating element is an element that can reachand maintain a dilated state but requires the use of an active dilatingelement to reach its dilated state, e.g., passive rolled foil, braidedmesh or covering membrane. In certain embodiments, the dilating elementmay additionally act as prosthesis to maintain the opening of the trackto the desired size. In preferred embodiments, the passive dilatingelement is used as both sheath for the active dilating element andprosthesis. In some of these embodiments the dilating element may alsoinclude multiple locking/release mechanisms to maintain the diameter ofthe dilating element to the desired track size, or release it to itsinitial reduced size to facilitate its removal from the track.

[0082] All of the dilating elements described herein may be used incombination with an outer protective cover. The cover may be rigid, suchas a mesh or braid, or flexible such as a silicon or latex membrane, ora combination of both. Some of the embodiments represented in theaccompanying figures of the dilating elements described below show sucha membrane or a protective oversheath while some others do not. It is tobe understood that all of these dilating elements may be used with sucha membrane or protective oversheath.

[0083] The integrated actuation mechanism includes a dial-a-sizestructure, and transmission mechanism for actuation of the dilatingelement. Both of these structures are connected and housed in a handlefor direct activation by the user.

[0084] The dial-a-size structure is an element that can adopt a varietyof positions or configurations within the handle such as a rotatingwheel, a sliding rod, or a series of push buttons, for example. Thedial-a-size structure is movably supported within a groove or recess ofthe handle. The movements of the dial-a-size structure are graduated byindices, markings, or reference marks thereon and on the handle. Theseparation between the indices markings, or reference marks is directlyproportional to a desired dilation size and are preferably graduated indiameter units or French units. The positions of the dial-a-size areselected by the user. The dial-a-size structure is also directlyconnected to the transmission mechanism, or it may be connectedindirectly if amplification of motion is desired.

[0085] Alternatively, the dial indirectly transfer motions on switchesor buttons from the user to the transmission mechanism. The dial mayinclude an electronic interface. For example, the electronic interfacecan include, but is not limited to, a power source, a circuitry, aseries of switches, and a motor, electricly connected within thecircuitry. The motor is connected to the transmission mechanism.

[0086] The transmission mechanism is a mechanical structure or acombination of several mechanical structures which transfers the motionapplied on the dial-a-size structure to the dilating element andoptionally converts it. For example, the transmission mechanism can be arod, a shaft or a hollow tube or a plurality thereof which transfers alongitudinal sliding motion of the dial-a-size to a sliding motion ofthe distal end of the dilating element. In this type of actuationmechanisms the dilating element is preferably an element which expandsradially when compressed longitudinally. Such dilating elementsincludes, but are not limited to, balloons, malecots, rubber tubes, meshand braids. Alternatively, the transmission mechanism 1) converts firstthe motion applied to the dial-a-size, then transfers the convertedmotion to the dilating element, 2) transfers first the motion applied tothe dial-a-size to the dilating element and then converts it beforeapplying the converted motion to the dilating element, or 3) convertsfirst the motion applied to the dial-a-size then transfers it to thedilating elements, and then converts it again before applying to thedilating element.

[0087] For example, the dial-a-size is a rotating wheel and the dilatingelement expands upon longitudinal compression. The transmissionmechanism converts the rotating motion into a longitudinal motion. Suchtransmission mechanism can be an axial rod, shaft or hollow tubeconnected proximally to the dial-a-size and distally to the dilatingelement. Either one of the proximal or distal connecting point isfixedly connected, the other one is movably connected by a thread orscrew structure such that upon rotation of the rod, the movablyconnected point move longitudinally. In some embodiments, the thread islocated at the proximal end of the rod and movably interacts with acorresponding complementary thread in the dial-a-size structure, and thedistal end is fixedly connected to the dilating element by a washer. Inother embodiments, the thread is located at the distal end of the rodand movably interacts with a corresponding complementary thread locatedor affixed to the dilating element, and the proximal end is fixedlyconnected to the wheel of the dial-a-size.

[0088] Optionally the rod may include a second thread to convert therotating motion in a longitudinal motion opposite to the firstlongitudinal motion to apply a greater and faster compression rate tothe dilating element and thus faster dilation. In this case, boththreads wind on the rod in opposite directions, clockwise andcounterclockwise, such that upon rotation of the rod oppositelongitudinal motions are applied to the dilating element. If theopposite longitudinal motions are converging the dilating element iscompressed and thus expands. If the longitudinal motions are diverging,the dilating element is released, and thus deflates or relapses to asmaller radius.

[0089] In some cases, the transmission mechanism is composed of a pairof rods which move concertedly either in a same direction or in oppositedirections. Alternatively, one rod remains fixed while the other movesbidirectionally. In some cases, the pair of rods is located axially. Inother cases, each rod is located at an opposite equidistant positionfrom the axis of the dilating element and is connected to thedial-a-size and the dilating element by a pivotal bar if oppositedirections of movement are desired, or by a fixed bar if concertedmotion is desired. Such transmission mechanism may be used incombination with dilating elements such as malecots and parallelograms,for example.

[0090] In yet other embodiments, the transmission mechanism is a valvewhich control the flow of a fluid entering a balloon chamber.

[0091] These and other types of mechanical structures which convert onetype of motion, e.g., lateral, rotational, longitudinal, etc., intoanother, with or without amplification or inversion of motion, are wellknown in the art and can be sized and adapted for use in the actuationcomponents of the instant dilation systems.

[0092] In summary, the present invention provides a single device forcontrolled radial expansion of a track of a patient, for example anephrostomy track. The invention also integrates a dilator and a sheathin one device. After initial entry with an 8F needle portion of thedevice, an expansion member provides high dilation forces controlled bya dial-a-size actuation system connected to dilation systems and thehandle. The device also provides over the wire type functionality, i.e.,permit passage of a guide wire. The benefits of the above-describeddevices also include true radial dilation by the expansion member andthe lessening of tissue trauma around the track area. The single stepprocedure eliminates the conventional exchange of dilator sheaths whileachieving track sizes from 8-30F through the use of a single device.

[0093] The inventive dilation systems, including the particularembodiments shown and described herein, may be adapted for use inendoscopic procedures. Instead of using a rigid element that connectsthe dilating/expansion element to the dial and handle, a flexible coilor wire can be used, making this invention and the various embodimentsdescribed herein applicable to endoscopic applications in thegastrointestinal and urologic lumens of the body for dilating stricturesand obstructions inside the body, for example.

[0094] The above dilation systems also can be utilized in the placementof PEGS, for opening constrictions in the vascular system or duringintervention in other organs and lumens of mammals. These described usesof the inventive dilation systems are preferable and exemplary and areby no means limiting. It is to be understood that other uses arecontemplated and within the scope of this invention.

[0095] These and other actuation mechanisms are further described andillustrated in specific embodiments disclosed below.

[0096] To form a track of desired size in a patient, the skin of thepatient is punctured with a needle for initial access. A guide wire isthen inserted in the track through the needle. Then, the dilatingelement is inserted in a compressed state into the track over the guidewire. Alternatively, the needles and the dilating element are insertedtogether. The needle then is contained within the dilating element andonly the sharp distal tapered tip of the needle protrudes from thedistal end of the dilating element.

[0097] Once the dilating element is inserted into the track of apatient, actuation of the dial by the user will initiate radialexpansion of the dilating element, thus dilating the track of thepatient. Motion of the dial by a certain amount, will actuate thetransmission mechanism and the dilating element of a proportionalamount. Thus dilation of the track is directly proportional to theamount of motion applied to the dial. Thus by marking and graduating thevarious positions of the dial-a-size in the handle, a user may selectthe desired amount of expansion applied to the dilating element, andthus the desired dilation.

[0098] Once the track is dilated to the desired size, a prosthesis orsheath may be inserted into the track to maintain the track opening, andthe dilating element is removed. Alternatively, the dilating element maybe both a dilating element and a prosthesis, in this case, there is noneed for this second step, and then the actuation mechanism isdisconnected from the dilating/prosthesis element.

[0099] Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

[0100] Tubular Radial Spring with Active Foil Torsional Element

[0101] In a first embodiment shown in FIGS. 1A-1D, a dilation system 100and related method according to the present invention includes aninstrument 100 (showing in FIG. 1C) having an active dilating element 10which can act as both a dilating element and a prosthesis. The dilatingelement 10 is a rolled or coiled foil which operates like a tubularradial spring 12. The spring 12 develops radial forces which are eitherdirected outward if the spring is compressed, or directed inward if thespring is expanded radially from its relaxed state. The spring 12 willthus preferably be used as an active dilating element in a compressedstate, and as a passive dilating sheath in an expanded state. The spring12 is formed by rolling one edge 14 of an elastic quadrangular plateover the plate toward the opposite edge 16 of the plate such that itforms a tube the cross section of which forms a spiral. The plate ispreferably of a foil type, either metallic or plastic, and is relativelyvery thin so that it can be spirally rolled, or coiled, into a tube. Thespring 12 (FIGS. 1A and 1C), in its wound or compressed state (FIG. 1B),is small in diameter, for example, about 8F. When released, the spring12 tends to unwind. The torsional strength of the spring 12 should begreater than the resistance offered by the tissue track so that thespring 12 dilates the tissue upon release. The controlled release of thespring 12 can be calibrated to provide a progressive continuous dilationforce, i.e., the same dilation force for each increments of release.

[0102] As shown in FIG. 1A, the spring 12 includes a locking mechanism.A series of circumferential slots 18 are cut in the spring 12 along itslongitudinal axis to retain small rivet-type structures 20 (FIGS. 1B-1C)that move inside the slots 18. The rivets 20 are mechanically linked toan actuating rod 22 contained within the spring 12 and connected to thedial 26 in the handle 24 for user actuation. The actuating rod 22 isconnected to a dial 26 with locking mechanism. As shown in FIG. 1C, uponrotation of the dial 26, the rivets 20 move in the slots 18, permittingthe release and enlargement of the spring 12 within the track of thepatient. FIGS. 3A and 3B show other embodiments of the rivets and slotslocking mechanism which may be used with a passive foil as describedherein after. FIG. 1D shows the enlarged spring 12 acting as aprosthesis to maintain the dilator size of the track opening to accessthe kidney percutaneously.

[0103]FIG. 2 shows a modified dilation system 100 using the active foilof the first embodiment. In FIG. 2, the spring 12 is tightly wound andmounted around a needle 28 and restrained from longitudinal movement bya washer 30 and a tip 32. A braid or mesh 34 surrounds the spring 12 andneedle 28 and is fixed to the needle 28 at the distal end 32. At itsproximal end 38, the braid is connected to a “dial-a-size” actuationmechanism 40 and handle 24. When the actuation mechanism 40 pulls thebraid tightly, radial expansion of the spring 12 is restrained. As thebraid is loosened, the braid moves distally (as represented by the thickarrow pointing to the left in FIG. 2) and expands radially due to thetorsional force supplied by the spring 12. The spring 12 expandsradially and the track of the patient is thereby opened. The loosenedposition of the braid 34 is shown by the outer thick dashed lines inFIG. 2. The radially expanded position of the spring 12 is also shown bydashed lines between the tip 32 and the washer 30. Thus actuation isachieved by pulling or releasing the braid 34. No slots 18 or rivets 20as shown in FIGS. 1A-1D are needed in the dilation system of FIG. 2.

[0104] It is also contemplated for the dilation system of FIG. 2 to actas a prosthesis or sheath to maintain the track opening after dilation.In this case, the braid 34 would be detachable from the distal end 36 ofthe needle by, for example, pulling the braid with sufficient force. Thetip 32 to the left of the spring 12 in FIG. 2 would not be incorporatedin this device so that the needle 28 could be pulled out, leaving onlythe spring 12 to act as a prosthesis. In this case, it may be necessaryto incorporate a locking mechanism such as slots 18 and rivets 20 ofFIGS. 1A-1D or any other locking mechanisms disclosed herein after andillustrated in FIGS. 3A-B, 4A-F, 5, and 6A-E into the device to restrainfurther radial expansion of the spring 12 once the desired track openingis reached.

[0105] The dilation system of this first embodiment, and shown anddescribed in connection with FIGS. 1A-1 and 2, has the followingadvantages:

[0106] a. True radial (continuous) dilation is obtained due to thecircumferential structure of the spring 12.

[0107] b. Differing sized tracks of desired diameters can be obtaineddue to the controlled release and actuation provided by the integratedhandle.

[0108] c. The “waisting” phenomenon that occurs during the use ofballoon catheters is avoided. In the present embodiment, the torsionalstrength of the spring 12 is sufficiently stronger than the resistanceoffered by the tissue, and the consistent tubular profile exerts thesame force on the tissue circumferentially and along the entire lengthof the spring 12. The spring 12, therefore, evenly opens the tissue.

[0109] d. Since the spring 12 opens outwardly, an annular space iscreated permitting passage of a guide wire 42 (not shown). In addition,as shown in FIG. 2, the spring 12 can be mounted onto an initial entryneedle 28 and introduced into the patient.

[0110] e. Due to the hollow annular space created upon enlargement ofthe spring 12, this dilation system may serve as a prosthesis tomaintain the track opening and eliminates the need for a separatesheath. Hence, this dilation system integrates a dilator and a sheath.

[0111] f. The removable handle includes a mechanism to comfortably allowthe calibrated and controlled release and enlargement of the spring 12,providing the “dial-a-size” functionality.

[0112] The spring 12 also can be used most optimally to act as both adilator and a sheath, or, in the alternative, used only as a universalsheath (in a prosthesis role) in conjunction with balloon or plasticdilators as described below.

[0113] The spring 12 shown in FIGS. 1A-1D and 2 can be utilized forother percutaneous access procedures to dilate and open the exteriorskin of a patient to obtain access inside the body. Although the abovediscussion involved maintaining a track size of 8F to 30F, the same foilstructure can be used for laproscopic and general surgery to dilate,open, and act as a prosthesis for access inside the body.

[0114] Passive Foil Torsional Element: Universal Sheath

[0115] In this embodiment, the dilation system 100 comprises both anactive and a passive dilating element. The passive dilating element is asheet of metal, for example, or any other material that presentsadequate properties, that is rolled into a tube such that the wall ofthe tube in cross section forms a spiral, with segments of its walloverlapping each other. In this embodiment, the spiral tube (hereinafter“universal sheath”) does not possess substantial torsional strength todilate spontaneously surrounding tissue and is thus preferably used incombination with the conventional plastic dilators or balloon cathetersor with any active dilating elements described herein. Alternatively,the universal sheath possesses a torsional strength only in the dilatedstate to permit the easy release of the dilated state to a smalleroriginal state to facilitate removal of the sheath from the track of thepatient. The sheath is manufactured by rolling a sheet of metal or othermaterial having appropriate flexible characteristics, around a cylinderto cover approximately 0.75-10 times the periphery of the cylinder.Preferably, the sheet winds 1.25-2 times the periphery of the cylinder.In the case of plastic dilators, an initial entry needle 28 initiatesthe track and an array of plastic dilators are exchanged to enlarge thetrack. The universal sheath 44 acts as a prosthesis to keep the trackopen. Although several dilators may be used, only one universal sheathis needed to act as the prosthesis. Various sizes of the sheath can beachieved via controlled dilation and/or release using in combinationwith the actuation mechanism any of a variety of locking mechanisms asillustrated in FIGS. 3A-B, 4A-F, 5, and 6A-E. The locking mechanisms maybe manufactured on the sheet prior to coiling it by a variety ofprocesses either integrated in the manufacturing of the sheet such asextrusion or cold draw, or in a separate step after manufacture of thesheet, such as stamping, machining, laser cutting photo etching, forexample.

[0116]FIG. 3A shows a cross-sectional view of the universal sheath 44with a rivet 20 and slots 18 as locking mechanism. Both overlappinginner segments 46 and outer segment 48 of the universal sheath 44comprise a series of spatially overlapping slots 18. The radius of theuniversal sheath 44 is controlled by the rivet 20 which providessufficient resistive friction forces to impede opposite radial movementsof the inner segment 46 and outer segment 48. Upon, the application ofprogressive radial forces provided by a dilating element such as aballoon catheter or other dilating devices as described herein,sufficient to overcome the resistive friction forces of the rivet 20,the inner segment 46 and outer segment 48 slide outwardly in oppositedirections, expanding progressively and continuously the radius of theuniversal sheath 44 and dilating the track opening of the patient. FIG.3B shows a cross sectional view of an alternate embodiment of theuniversal sheath 44 with rivets 20 and slots 18 as locking mechanism. Inthis embodiment, only a series of slots 18 is located on the innersegment 48 of the universal sheath 44. The outer segment having a seriesof holes 50 not wider than necessary to hold the rivets 20 therethrough.An alternate embodiment (not shown) would present the series of slots 18on the outer segment 48 and the series of holes 50 on the inner segment46. Expansion of the universal sheath 44 is activated as described forFIG. 3A with the sliding of only one segment, the segment having theslots 18.

[0117] FIGS. 4A-F show various embodiments of another type of lockingmechanism for use in the passive universal sheath using a plurality ofinterfacing recesses 52 and bumps 54. The recesses 52 and bumps 54 maybe present on either one of both of the inner and outer surfaces 56 and58, respectively of either one of both inner and outer segments 46 48,respectively. In FIG. 4A, the recesses 52 and bumps 54 are present onboth surfaces 56 and 58 of both segments 46 and 48 such that clampingwould occur regardless of which segment is the inner or outer segment.In FIG. 4B, the recesses 52 and bumps 54 are present on only one surfaceof each segment, i.e., the inner surface 56 of the outer segment 48 andthe outer surface 58 of the inner segment 46. In this embodiment,clamping occur only when the inner surface 56 of the outer segment 48 ispositioned on top of the outer surface 58 of the inner segment 46. Suchembodiment would permit the easy release of the universal sheath 44 fromthe track of the patient once no longer needed by dilating the sheath soboth edges 14 and 16 slide by each other and the position of the innerand outer segments is reversed such that the inner segment 46 becomes anouter segment 48′, and the outer segment 48 becomes an inner segment46′. In this reverse configuration no clamping occurs and the sheath canbe contracted by an activating mechanism and released from the trackwith minimal shearing to the tissue. To avoid excessive dilation of thetrack prior to releasing the sheath, it is preferable to imprint orpositioned the recesses 52 and bumps 54 the closest as possible of theedges 14 and 16 of the foil. To obtain a good grip or clamping betweenthe surfaces 56 and 58 and to facilitate the reversion of the segment'sposition, the foil is preferably manufactured so as to form a “G” asshown in FIG. 4C with the recesses 52 and bumps 54 or tongues 60 pointedaway from each other, where the original folding of the foil is in areverse configuration. The segment's positions are then reversed asshown in FIG. 4D to bring the surfaces bearing the recesses 52 and bumps54 or tongues 60 in overlapping configuration such that clamping occurs.

[0118]FIGS. 4E and 4F show alternative forms of recesses 52 and bumps 54which may be used to provide clamping or locking of the sheath 44.

[0119]FIG. 5 shows a portion of a cross sectional view of an embodimentfor releasing the dilated state of the universal sheath to a compressedor resting state with a lower diameter. In this case the universalsheath 44 is further fitted on the inner edge 14 of the foil with atrigger 62. The trigger 62 is an elongated rod having a groove 64 whichwraps around the edge 14 of the inner segment 46. At one of the edge ofthe groove 64, the trigger 62 also has at least two bumps 54 and 66which fit into the recesses 52 and bumps 54 of the inner surface 56 ofthe outer segment 48. When bump 54 is engaged in a recess 52 the triggeris in a resting position, and operates as a lock such that no sliding ofthe inner and outer segments occurs (as shown on FIG. 5). When thetrigger is pivoted as shown by the arrow, bump 66 is now engaged in oneof the recesses 52 with the trigger now lifting the edge 14 away fromthe inner surface 56 of the outer segment 48, and disengaging the bumpsof the inner segments 46 from the recesses 52 outer segment eitherdirections of both segments is thus facilitated permitting the dilationor contraction of the sheath. The trigger 62 is connected to the handle24 (not shown) and can be activated by the user either directly orindirectly.

[0120]FIG. 6A shows a cross sectional view of another embodiment of thelocking mechanism for use with the universal expandable sheath. In thisembodiment, the outer segment 48 includes a series of tongues 60partially cut out from the foil and bend toward the inner segment 46 tofit within spatially overlapping recesses 52. In this embodiment themovement of the edges 14 and 16 is bidirectionally restrained.Alternatively the position of the recesses 52 and the tongues 60 may bereversed with the tongues 60 being located on the inner segment 46 andhaving an inverse curvature with regard to the foil or even no curvatureat all, and the recesses 52 being located on the outer segment 48.

[0121]FIG. 6B shows an alternate embodiment of the locking mechanism ofFIG. 6A for unidirectional restraint of movement of the edges 14 and 16of the sheath 44 to provide locking of either dilation or contraction ofthe sheath.

[0122]FIG. 6C shows a top view of a tongue 60 and FIG. 6D shows a topview of a recess 52 of FIG. 6B. FIG. 6E shows a prospective view of thesheath having a series of recesses 52 disposed along the length andseparated by discrete increments to provide discrete dilation of thesheath by increment of a portion of French unit.

[0123] In another embodiment of the universal sheath, the sheath isformed by winding less than 1 time around a cylinder or is made of acannula or needle having a longitudinal slot 19 as shown in FIGS. 7A-7E.Enclosed within the sheath 44 is a torsional spring 12. The spring 12 isconnected along its length by its outer edge 16 to an edge of thelongitudinal slot 19 of sheath 44. The spring 12 is connected at itsproximal end 38 to an actuation mechanism that includes a control buttonor dial 26 and indices 27 graduated in French (F) units. Rotation of thedial 26 applies a torque to the torsional spring 12 to expand the sheath44 from its initial position shown in FIG. 7A to its expanded positionshown in FIG. 7B. Through the use of the control button and indices, thesheath 44 can be expanded to a desired diameter of a track of a patient.

[0124] The universal sheath 44 as described above may be used with avariety of known dilating elements, such as passive dilators or balloonscatheters. For example, the universal sheath 44 can act as an initialovertube through which all plastic passive dilators are passed. Theuniversal sheath 44 acts as a buffer to minimize the tear to the tissueassociated with the introduction of the bullet tipped plastic-dilators.Also, the universal sheath 44 may be used with any of the dilatingelements as disclosed further herein. For example, FIGS. 8A-81 showsvarious dilating elements which may be used in accordance with thepresent invention to provide a progressive continuous dilationcontrolled by the user through an activation mechanism and adial-a-size. FIG. 8A shows another embodiment of the universal sheath 44in combination with the spring 12 described above. FIGS. 8B-81 showvarious embodiments of dilating elements which convert a longitudinalforce or movement into a lateral one or radial one. If the dilatingelement is a planar element, the longitudinal movement is converted intoa lateral movement and the universal sheath then convert the lateralmovement into a radial one. If the dilating element is cylindrical oroccupies a cylindrical volume, the longitudinal movement is converteddirectly into a radial one. Appropriate embodiments include, but are notlimited to, malecots or slotted tubes shown in FIGS. 8B and 8C,parallelograms shown in FIGS. 8D and 8E, jacks or articulated systemsshown in FIGS. 8F and 8G, rubber sheaths or rubber supports shown inFIGS. 8H and 81. Detailed description of some of these embodiments isprovided herein below and in the following sections. In theseembodiments, the compression of the dilating element by the applicationof axial forces in opposite directions at the distal and proximal ends36 and 38, respectively, of the dilating element creates radial orlateral forces.

[0125] Activating mechanisms to create compression of a dilating elementcan be a central rod 68 connected to the dilating element axiallythrough a lumen by either threads 70 or washers 72 see FIGS. 8G-81 or byarticulated joints 74 as shown in FIG. 8F. The rod 68 may include twothreaded segments 76 and 78, a proximal thread 76 for the proximal end38 of the dilating element and a distal thread 78 for the distal end 36of the dilating element. Both threads 76 and 78 are directed in oppositedirections, for example, the proximal thread directed clockwise and thedistal thread 78 directed anti-clockwise, so that rotation of the rod 68would impart opposite motions of the proximal and distal ends of thedilating element. Alternatively the rod may include only one thread ateither one of the proximal or distal end of the dilating element. Theremaining end would be maintained stationary by a washer 72 secured tothe rod 68. The rod 68 is connected to the dial-a-size 26 in the handle24.

[0126] Other Active Dilating Elements

[0127] In addition to certain embodiments of the present inventiondescribed above, certain active dilating elements are provided that alsoprovide progressive radial dilation along the length of the track foruse with the actuation mechanism in a single device. As in the previousembodiments above, these eliminate the use of various size balloons orthe exchanges of the renal plastic dilators. Each of these dilatingelements comprises any of a variety of mechanical structures mountedonto an initial entry needle or passed over the initial entry needle.Depending on the type of dilating element, different actuationmechanisms as described earlier may be needed and designed into thehandle.

[0128] Malecots:

[0129] FIGS. 9A-9I. show a dilation system 100 having a series ofmalecots 80 as dilating element 10 mounted onto a needle 28 and guidewire 42. A malecot is a tube having radial arms 82 formed between slots84 in the tube as dilating element. The malecot may be made of metal,rubber, or other suitably flexible material. It is contemplated thatNitinol (a nickel titanium alloy) would be a suitable material for amalecot or any of the other mechanical dilating elements describedfurther herein.

[0130] When the malecot 80 is axially compressed, the arms 82 deflectradially outward to expand the malecot radially. This radial expansionprovides the dilation force. A meshed braid, a sheath or other suitablecovering 86 may be placed over a series of malecots sequentially stackedto provide a regular surface for dilation along the length of thedilating element 10.

[0131] The actuation mechanism includes a rod or hollow cannula having ascrew mechanism with external threads that engage internal threads ofthe dial-a-size, for example (not shown). The hollow cannula 88containing the needle 28 is connected to the dial 26. The distal end 90of the cannula 88 abuts the most proximal malecot 92.

[0132] To form a track of a desired size in the patient, the needle 28punctures the skin for initial access. A guide wire 42 is inserted intothe initial track. The dilating element 10 (series of malecots) isinserted into the track over the guide wire 42. Rotation of the dial 26then advances the cannula 88 distally to compress the malecots 80.Rotation of the dial 26 by a predetermined degree advances the cannula aspecific distance to compress the malecots proportionally. Compressionof the malecots forces a radial expansion of the malecots, dilating thetrack of the patient of a certain amount which is directly proportionalto the applied rotation on the dial 26. Thus dilation of the track isdirectly and effectively controlled by the user with the dial-a-sizeelement. Once the track is opened to a desired size, the prosthesis 94is inserted into the track to maintain the track opening. For example,the prosthesis 94 may be of a size so that it may be slipped between theexpanded malecots 80 and the track. The dilating element is thenremoved.

[0133] Alternatively, the malecots may be dilated in their natural stateand radially compressed when their extremities are stretched this typeof malecots is also referred to as wire basket. The most distal malecot91 is fixed to the initial entry needle 28. A cannula 88 is attached tothe most proximal malecot 92. When the series of malecots is firstintroduced into the track, the cannula 88 is pulled proximally so thatthe malecots are in a generally elongated state. Axial displacement ofthe cannula 88 in the distal direction permits the malecots to expandradially and thereby expand the track of the patient. The amount ofexpansion is controlled by a dial-a-size 26 which is connected to thecannula 88.

[0134] Wire baskets which may be used as dilating elements in the deviceof the present invention have been disclosed in the U.S. Pat. Nos.4,590,938 and 5,496,330 for example as well as in U.S. patentapplication Ser. Nos. 08/656,010, 08/968,906, 09/064,704, 09/064,997,and 09/084,135, the disclosures of which are incorporated in theirentirety herein by reference.

[0135] Transmission Mechanisms for Malecots

[0136] In the dilation system of FIGS. 9A-9I, the malecots 90 are notcompressed independently. FIGS. 10A-C, 11-13 show a transmissionmechanism in which the malecots are compressed independently to ensurethat the radial expansion of each malecot is substantially the same.FIG. 10 shows two D-shaped needles 96 and 98 abutting one another ontheir flat faces 110. Each D-shaped needle includes a series ofprotrusions 120 forming grooves 130. Alternatively, the protrusions 120and grooves 130 spread along the half-circumference of the needle toprovide a proportionally radially distributed compression force on themalecots 80. The needles 96 and 98 are attached to a dial-a-size 26 inthe handle 24. Relative axial movement between the two needlescontrolled by the actuation mechanism causes the malecots 80 to compresslongitudinally and expand radially widening a track of a patient. Inthis dilation system, the malecots can be covered by a meshed braid, ora universal sheath 44 as described earlier or by other suitablestructures.

[0137]FIG. 11 shows a partial view of a transmission mechanism similarto that of FIGS. 10A-C. In FIG. 11, two round needles 28 and 29 arestacked side by side. Each end 140 and 150 of each malecot is retainedbetween or connected to a small flat ring 160. The ring 160 at one end140 of the malecot 80 is crimped, glued, or otherwise fixedly connectedto the first needle 28, and the at other end 150 of the malecot 80 iscrimped, glued, or otherwise fixedly connected to the second needle 29.As with the needles 96 and 98 of FIG. 10A, the needles 28 and 29 of FIG.11 are attached to a dial-a-size 26 in the handle 24. Relative axialmovement between the two needles 28 and 29 controlled by the dial 26causes the malecots 80 to compress and expand radially to open a trackof a patient. In this dilation system, the malecots 80 can also becovered by a meshed braid, a universal sheath 44 or by other suitablestructures,

[0138]FIG. 12 (side view) and FIG. 13 (cross-sectional view of FIG. 12)show a transmission mechanism similar to that of FIG. 11. In FIGS. 12and 13, two round needles 28 and 29 are arranged side by side withseparation there between. Each end 140 and 150 of each malecot 80 isretained between or connected to two washer 72 and 73 having holestherein to allow the needles 28 and 29 to pass through: The washer 72 atone end 140 of the malecot 80 is fixed to the first needle 28 via a ring160 that is crimped, glued, or otherwise fixedly connected to the firstneedle 28. The washer 73 at other end 150 of the malecot 80 is fixed tothe second needle 29 via a ring 160 that is crimped, glued, or otherwisefixedly connected to the second needle 29. The needles 28 and 29 areattached to a dial-a-size 26 in the handle 24. Relative axial movementbetween the two needles 28 and 29 controlled by the actuation mechanismcauses the malecots 80 to compress and expand radially to open a trackof a patient. As with the dilation systems of FIGS. 10-11, in thisdilation system, the malecots can be covered by a meshed braid, auniversal sheath 44 or other suitable mechanical structures, such asthose described further herein.

[0139] Other Malecot Structures:

[0140] The malecots 80 can include any number of shape of slots 84. Forexample, slots 84 may be shaped to intrinsically limit the radialdeflection of the malecots by using a H shape. The malecot shown inFIGS. 14A and 14B may be used alone as shown in FIG. 14A or in a seriesas shown in FIGS. 14B-C and may use the same actuation mechanism asdiscussed above and shown in FIGS. 9A-9I, 10A-C, 11 and 12.

[0141] The expansion of intrinsically limited-deflection malecots isillustrated in FIGS. 15A and 15B. A dilating element 10 having a seriesof such malecots is shown in FIG. 16. The malecots 80 include two arms82, positioned 180 degrees from one another, and two opposing fingers170 which define H-shaped slots 84. In the uncompressed state, thefingers 170 are not in contact, as shown in FIG. 15A. As the malecot iscompressed, the fingers 170 draw closer until they contact each other asshown in FIG. 15B. Upon contact, the fingers 170 do not deflect andthereby limit further radial expansion of the malecot.

[0142]FIG. 17 shows a cross sectional view of a half malecot 180 mountedon a rod 68. Expansion of half-malecot is actuated by pulling wires 190.The half-malecot may be used in a series and use a common or separateactuation system for each half-malecot.

[0143] Meshes or Braids:

[0144] Mesh or braid may act as dilating element by radially expandingupon axial compression. In FIGS. 18A-18C the mesh 34 may be covered by amembrane 200 that is fixedly connected to a hollow cannula 88 at aproximal end and fixedly connected to the needle 28 at a distal end. Themembrane 200 restrains radial expansion of the mesh 34. Axialdisplacement of the cannula 88 in the distal direction axiallycompresses the mesh 34 and causes the mesh to radially expand, openingthe track of the patient.

[0145] Expansion of the mesh or braid 34 through axial compression maybe also controlled by an overtube 210, as shown in FIG. 19. The overtubedefines the length of the mesh that will dilate. The tube 210 may bedisplaced axially in either the proximal or distal direction to limitradial expansion to only certain areas of the mesh and thus control thelength of the dilating element.

[0146] Parallelograms:

[0147]FIG. 20 shows a pair of rigid parallel rods 220 and 230 connectedto each other by a pair of rigid links 240 and 250 in a parallelogramarrangement. The links 240 and 250 are pivotally connected to the needle28 and to the rods 220 and 230. Although not shown in FIG. 16, it iscontemplated that this dilation system includes a plurality of suchparallelogram arrangements radially spaced around the needle, preferablysix or eight rods forming three or four parallelograms, respectively.Actuation of the parallelograms through pull wires, bars, or any othersuitable transmission mechanism causes the links 240 and 250 to rotateabout pivot points 260 and 270, causing the rods 220 and 230 to displaceradially and dilate a track of a patient.

[0148]FIG. 21 shows another parallelogram system having a plurality ofrigid parallel rods 220, preferably six, mounted around a needle 28 bydistal and proximal rubber supports 280 and 290, respectively. When therubber supports 280 and 290 are compressed, for example, by a cannula 88as in FIGS. 9A-91, the rubber supports radially expand to force the rods220 to displace radially and dilate a track of a patient. This type ofparallelogram operates like a malecot except that the dilation forcesare applied regularly with the same intensity along the length of therods. The rods and links of FIGS. 20 and 21 are made of metal or anyother suitable rigid material. Parallelograms may be used in combinationwith a mesh or braid, universal sheath 44 or any other suitablematerial.

[0149] Jacks:

[0150]FIG. 22 shows a dilation system having a jack actuated by athreaded needle. The jack is composed of a series of articulated rods300 connected between each other by joints 302 and connected to a ring160 at the proximal end and a nut 310 at the distal end. Preferably thejack has one, two or four joints 302. The ring 160 is movably supportedaround the needle 28 so rotation of the needle 28 does not impart motionto the ring 160. The ring 160 is spatially immobilized by a cannula 88(not shown). The proximal end of cannula 88 rests against the handle 24(not shown) and the distal end of cannula 88 rests against the proximalend of the dilating element. The nut 310 has a thread (not shown) whichengages with the thread 320 of the needle 28. Upon rotation of theneedle 28, the nut 320 is displaced axially along the needle 28compressing the articulated rods 300 forcing them to move radiallyoutward, thus dilating the track of a patient. A reverse motion of theneedle 28 would release the compression forces on the articulated rods300 and allow the release of the dilated state.

[0151] Alternatively, the jack comprises two nuts 310 having oppositethreads to engage two opposite threaded portion 320 on the needle 28.Rotation of the needle 28 imparts a converging or diverging motion ofthe nuts 310 dilating or releasing the jack.

[0152] Preferably the jack comprises a plurality of articulated rods 300radially distributed around a central axis to provide a regulardistribution of the dilating forces along the circumference of thetrack. Preferably the jacks comprises six to eight articulated rods 300.A dilating element can comprise one jack or a plurality of jacksarranged in a series along the cannula 88. Jacks may be used incombination with the mesh or braid, universal sheath 44, or any othersuitable material.

[0153] Pivots:

[0154] In FIGS. 23A and 23B, a plurality of pivots 330, are pivotallyjoined to the needle 28 at varying angular orientations around the axis.Actuation of the pivots 330 by a pull wire 190 (not shown), or othersuitable actuator, causes the pivots 330 to rotate about their pivotpoint 340 causing their extremities 242 and 244 to move radiallyoutward. A braid mesh or universal sheath can be placed over the entirestructure to obtain continuous and regular dilation. Pivots may be usedin combination with a mesh or braid, universal sheath 44 or any suitablematerial.

[0155] Chain Links:

[0156] In FIGS. 24A-24D, a series of chain links 350 are pivotallyconnected to each other head-to-tail, forming a chain, by a pin 380 orrivet or any other suitable connecting element. Each link 350 includes aprotrusion 360 at each end and a hole within the protrusion. A pull wire190 is connected to each link 350 by a hole 390 in the middle of eachlink (not shown) so that the links are aligned axially when the pullwire 190 is in a relaxed state. When the wire 190 is pulled to a tensestate, the links pivot with respect to one another and assume theformation shown in FIGS. 24C and 24D to dilate a track of a patient.Chain links may be used in combination with a mesh or braid, universalsheath 44 or any other suitable material.

[0157] Coiled Spring:

[0158]FIG. 25 a coiled longitudinal spring 400 is fixed at its distalend to the needle 28 and at its proximal end to a cannula 88. The spring400 is preferably made with Nitinol (NiTi). The spring 400 is introducedinto the track of a patient in a relatively stretched, tense state. Thespring 400 is then released by sliding the cannula 88 axially over theneedle 28 in the distal direction. The spring thereby radially expandsto dilate the track of a patient. Coiled springs may be used incombination with a mesh or braid, universal sheath 44 or any othersuitable material.

[0159] Telescopic Dilators:

[0160] A set of sliding telescopic cannulas may be integrated into asingle device similar in structure to a telescopic car antenna. Thecannulas are introduced into a track of a patient sequentially over aneedle to progressively dilate the track. In FIGS. 22A-F, threetelescopic cannulas 410, 420, and 430 are arranged over a guide needle28. Each cannula has a longitudinal slot 450 to allow sliding of amoving index or pin 440 within, when the cannula is disposed at theproximal end of the dilation system 100, and to allow sliding of thecannulas from a retracted position through a fixed index 460 to attainan extended position in the track of the patient. Each cannula alsopossesses a radial slot 470 in an “L” shape at their proximal end topermit locking of the cannula in the extended position, by sliding thefixed index 460 therethrough.

[0161] To dilate the track of a patient, the smallest cannula 410 isfirst rotated to engage its longitudinal slot 450 over the fixed index460, then a movable index 440 is used to push the cannula 410 within thetrack. The movable index 440 sliding through the longitudinal slots 450of the outer cannulas 420 and 430. Finally, the cannula 410 is rotatedback to engage radial slot 470 into the fixed index 460 and lock thecannula 410 in its extended position. This sequence is repeated witheach of the other cannulas 420 and 430 as shown in the FIGS. 22A-E,until the desired track size is reached.

[0162] The movable index 440 may be actuated directly by the user, or byan actuation mechanism as described herein above such as rods connectedto a dial in the handle (not shown).

[0163] Waistless Variable Dilation Balloons

[0164] In most cases, current balloons adequately dilate tissue mediumwhether it be surrounding a natural body lumen or a percutaneous track.However, there are two drawbacks associated with the use of currentballoons. First, when dense scar tissue is encountered, higher pressureis utilized to overcome the resistance of the scar tissue, and formationof a waist in the balloon is observed. Second, current balloons work ata rated pressure and inflate to a fixed size. This means that, dependingon the anatomy and the clinical setting, a set of several balloons hasto be kept on hand to meet the varied needs.

[0165] The waistless variable dilation balloons described hereinovercome these drawbacks by the use of a single device using a useractuation mechanism according the present invention.

[0166] Referring to FIGS. 27A-E, the waistless variable dilationballoons are composed of a tubular mesh 34 that surrounds a balloon 480and is attached by adhesive, swaging or other means at its proximal endto the distal end of a cannula 88 disposed withing the longitudinalgroove 500 of the handle 24 and dial 26 of the dilation system 100. Themesh 34 is initially pulled tightly over the balloon 480 to achieve alow profile. The balloon 480 is attached at its proximal end to acatheter 43 which is disposed within the lumen of cannula 88 and thegroove 500 and extend to the proximal end of handle 24. Catheter 43carries fluid to the balloon from port 490 at proximal end of catheter43. Catheter is fixedly attached to handle 24 along groove 500.

[0167] The cannula 88 fits into a longitudinal groove 500 extending fromthe circumference to the axis in the handle 24 and dial 26 shown in FIG.27A, C and D, FIGS. 28A-D, FIGS. 29A-D. The cannula 88 has a disk 510shown in FIGS. 30A-D which is fixedly connected to cannula 88 and locksinto a transversal groove 520 positioned in the distal end of the dial26 and covered by a cap 530, shown in FIGS. 27A-D and FIGS. 31 A-D, thatfits into a recess 540 shown in FIGS. 29A-D located on the halfcircumference of the proximal end of the dial 26 above the transversalgroove 520. The cap 530 has a matching transversal groove 550 that fitsatop the disk 510 of the cannula 88. Also the cap has two holes 560 forscrewing, nailing or otherwise fixing the cap 530 on the dial 26 in therecess 540. The dial 26 also has two holes 570 located on each side ofthe transversal groove 520 for fixing the cap 530 on the dial 26.

[0168] The mesh 34 is fixedly connected to the catheter 43 at the distalend. The mesh 34 is retained and fixed to the distal end of the cannula88. Shown in FIG. 30D and FIGS. 32A-D, the cannula 88 is further fittedat its proximal end with a tongue 580 that protrudes radially andstretches longitudinally along a portion of the length of the cannulafor sliding within the longitudinal groove 500 of the handle 24 dial 26.The tongue 580 locks rotational movements of the cannula 88 and avoidrotational distortions of the mesh 34. Further the tongue 580 serves asan index, with reference to the markings 27 graduated in unit of Frenchon the handle 24.

[0169] The distal end of the handle 24 has a circular protrusion 590 thesurface of which is threaded 600 an fits into the thread 610 of an axialcircular recess 620 of the dial 26 as shown in FIG. 27E.

[0170] Circular motion of the dial 26 advances distally or proximallythe dial 26 along the protrusion 590 of the handle 24. Longitudinalmotion of the dial 26 is transferred to cannula 88 by the disk 510locked in groove 520 and 550. Longitudinal motion of the cannula 88toward the distal end of dilation system 100 loosens the mesh 34allowing the balloon 480 to expand upon entry of dilating fluid withinthe balloon 480 though the port 490 and catheter 43. Longitudinal motionof the cannula 88 toward the proximal end tightens the mesh 34 aroundthe balloon 480 restricting expansion of the balloon 480.

[0171] Unlike standard balloons, where only radial forces are at play,the use of an overlaid mesh 34 in the waistless balloon compacts theballoon and creates dilation forces having both longitudinal and radialcomponents. Higher pressure can now be applied to the balloons 480 andthe mesh 34, maintaining the pressure throughout the length andcircumference of the dilating element 10, forming minimal or no waist.

[0172] Alternatively the protrusion 590 and the recess 620 do not havetheir surfaces threaded as shown in FIGS. 28A-D. Relative longitudinalsliding motion of the dial 26 vis-a-vis the handle 24 transfers themotion to the cannula 88 which then dilates or loosens the mesh 34.

[0173] Referring to FIGS. 33A-B, optionally the dilation system may befitted with a universal sheath 44, that is slid over the inflatedballoon to maintain the track opening. The balloon 480 can then bedeflated and the mesh 34 longitudinally tensed to remove the dilationsystem from the track.

[0174] FIGS. 33A-B shows an alternate embodiment of the waistlessvariable dilation balloon as a dilating element of the dilation systemsof the invention. In this embodiment, the mesh 34 is fixed proximally tothe distal end of the handle 24 and distally, to the distal end of thecannula 88 by a washer 72. The washer 72 locks relative longitudinalmotions of the cannula 88 and the distal end of the mesh 34 but allowsfree rotational motions of the cannula 88 without imparting theserotational motions to the mesh 34 thus avoiding rotational distortion ofthe mesh.

[0175] The proximal end of the cannula 88 has a thread 78 which engageinto a corresponding thread 77 in the handle 24. The proximal end of thecannula 88 is further fitted with a dial button 26 bearing an index 27which when activated by the user, adopt a plurality of radial positionsin reference with the marking indices 27 on the handle 24. FIG. 34Ashows the deflated state of the dilating element with the cannula 88pushed distally. FIG. 34B shows an inflated state of the dilatingelement with the cannula pulled proximally. Waistless variable dilationballoons may also be made with the universal sheath 44 as covering forthe balloons in place of the mesh 34.

[0176] Dilation Method with Forced Expansion:

[0177] Forced expansion may be carried out using a dial-a-size typeactuation mechanism according to the present invention. These forcedexpansion methods force the track to open through a shearing type actionsimilar to the use of conventional renal dilators, instead of theprogressive radial expansion applied by the dilation systems describedabove. As opposed to the renal dilators, however, only one dilationsystem with a dilating element actuated by a dial-a-size actuationmechanism is needed to open the track to a desired size.

[0178] For example, a single malecot may be used as dilating elementwith the forced expansion methods. The malecot has the sameconfiguration as, for example, that shown in FIG. 14A. The malecot isfirst introduced into the track, dilated, and then pulled out of thetrack to gradually dilate the entire length of a track. Other dilatingelements described above can be used in a similar fashion.

[0179] Alternatively, a malecot, or other dilating element may bedilated outside of the body and then forced through the track opening.The desired diameter of dilation is adjusted before each introduction ofthe dilating element.

[0180] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the dilation systems andmethods of the present invention and in construction of the dilationsystems without departing from the scope or spirit of the invention.

[0181] Other embodiments of the invention will be apparent to thoseskilled in the art from consideration of the specification and practiceof the invention disclosed herein. It is intended that the specificationand examples be considered as exemplary only, with a true scope andspirit of the invention being indicated by the following claims.

What is claimed is:
 1. A dilation system for dilating a natural orcreated track of a body, the dilation system comprising: a dilatingelement for insertion into the track of the body, said dilating elementbeing radially expandable to any of a plurality of diameters; and anactuating mechanism connected to said dilating element for controllingthe radial expansion of said dilating element to any of the plurality ofdiameters.
 2. The dilation system of claim 1, wherein said dilatingelement comprises a spiral shaped foil.
 3. The dilation system of claim2, wherein said dilating element comprises a plurality of lockingelements.
 4. The dilation system of claim 3, wherein said plurality oflocking elements comprise at least two series of bumps and recessesextending longitudinally, one of said at least two series of bumps andrecesses is disposed at least on an interior surface of an outer segmentof the foil and the other of said at least two series of bumps andrecesses is disposed at least on an exterior surface of an inner segmentof the foil, said at least two series of bumps and recesses overlayingspatially to provide any of a plurality of locked positions.
 5. Thedilation system of claim 3, wherein said locking elements comprise aseries of interfitting tongues and recesses disposed longitudinallyalong the foil.
 6. The dilation system of claim 5, wherein said tonguesare partially cut out from an outer segment of the foil and pointingtoward an inner segment of the foil, and said recesses are disposed onan outer surface of an inner segment of the foil.
 7. The dilation systemof claim 5, wherein said tongues are partially cut out from an innersegment of the foil and pointing toward an outer segment of the foil,and said recesses are disposed on an inner surface of an outer segmentof the foil.
 8. The dilation system of claim 3, further comprising atrigger engaging between said at least two series of bumps and recesses,for engaging or releasing engagement of one of said at least two seriesof bumps and recesses with the other of said at least two series ofbumps and recesses.
 9. The dilation system of claim 3, wherein saidlocking elements provide unidirectional locking of motion.
 10. Thedilation system of claim 3, wherein said locking elements providebidirectional locking of motion.
 11. The dilation system of claim 2,wherein the dilating element further comprises a second spiral shapedfoil.
 12. The dilation system of claim 11, wherein said second foil actsas a dilating element.
 13. The dilation system of claim 11 wherein saidsecond foil act as a sheath.
 14. The dilation system of claim 2, whereinthe dilating element further comprises a second dilating elementselected from the group consisting of malecots, jacks, parallelograms,balloons, wire baskets, pivots, chain links, meshes and braids.
 15. Thedilation system of claim 2, wherein said dilating element furthercomprises a balloon.
 16. The dilation system of claim 1, wherein saiddilating element comprised a balloon and a mesh or a braid.
 17. Thedilation system of claim 1, wherein said dilating element comprises atleast one malecot.
 18. The dilation system of claim 1, wherein saiddilating element comprises at least one jack having at least two seriesof radially articulated rods.
 19. The dilation system of claim 1,wherein said dilating element comprises a series of telescopic cannulas.20. The dilation system of claim 1, wherein said actuation mechanismcomprises a dial and a transmission mechanism connected proximally tosaid dial and distally to said dilating element.
 21. The dilation systemof claim 20, wherein said actuation mechanism further comprises indices.22. The dilation system of claim 20 wherein said transmission mechanismtransfers a longitudinal motion, rotational motion, or a combinationthereof of said dial to said dilating element.
 23. The dilation systemof claim 22, wherein said transmission mechanism comprises at least onetubular member selected from the group consisting of a cannula, a rod, ashaft, and a needle.
 24. The dilation system of claim 22 wherein saidtransmission mechanism converts and transfers a rotational motion ofsaid dial to said dilating element.
 25. The dilation system of claims24, wherein said transmission mechanism comprises at least one tubularmember having at least one thread.
 26. The dilation system of claim 25,wherein said thread is disposed on a proximal portion of said at leastone tubular member for engagement with said dial.
 27. The dilationsystem of claim 25, wherein said thread is disposed on a distal portionof said at least one tubular member for engagement with said dilatingelement.
 28. The dilation system of claim 25 wherein said transmissionmechanism further comprises a second thread.
 29. The dilation system ofclaim 1, further comprising an expandable covering disposed around saiddilating element.
 30. The dilation system of claim 29, wherein saidexpandable covering is selected from the group consisting of meshs,braids, membranes, and foils.
 31. A method for dilating a track of abody, said method comprising the steps of: a. inserting a dilatingelement capable of expanding to any of a plurality of diameters; b.expanding said dilating element to any of the plurality of diameters byproximally actuating an actuation mechanism connected distally to saiddilating element, thereby causing said dilating element to reach adilated state and dilating the track of a body to any of the pluralityof diameters.
 32. The method of claim 31 further comprising the step of:c. introducing a sheath over said dilating element in a dilated state tomaintain the track of a body dilated to said any of a plurality ofdiameters.
 33. The method of claim 32 further comprising the step of: d.removing said dilating element from the track of a body.
 34. The methodof claim 33 further comprising the step of: c. deflating the dilatingelement from said dilated state to any of a plurality of diametersinferior to the diameter of said dilated state.
 35. The method of claim31 wherein step a is performed before step b.
 36. The method of claim 31wherein step a is performed after step b.